Lubricant



March 7, 1944. A. BEERBOWER ETAL 2,343,737

LUBRICANT Filed Sept. 5, 1942 FATTY LUBRI eATmc HYDRA' 'E A6181? on. LlME HEATING MHXING MIXlNG FINISHED CREASE Patented Mar. 7, 1944 LUBRICANTAlan Beer-bower, Kenllworth,

Glen Burnie, Md., assignors to Standard pany, a corporation of Barley,

Oil Development Com Delaware N. J., and Ralph E.

Application September 5, 1942, Serial No. 457,380

3 Claims.

This invention relates to novel lubricants and methods of preparingsame, and more particularly it relates to manufacturing cold made cupgreases in a two-stage process.

In making cup greases by the usual cold process. the lime is suspendedin a small part of the oil, while the balance of the oil and the fattyacid are heated to about 190 F. The lime suspension is then added to theacid solution, and reaction takes place. The term cold" refers to thefact that the material is never heated above the boiling point of water.

A troublesome feature of the above process is the fact that during thereaction a gas of some sort is released causing a thick layer of foam toform on top of the grease. This is particularly true in high viscosityoils. This foam if not removed works into the grease and spoils itsappearance.

It is believed that this foam is due to the reaction of a small amountof low molecular weight fatty acids in the commercial fatty acids used,with the calcium carbonate traces found in the lime; generally allcommercial hydrated lime contains traces of calcium carbonate.

It is a primary object of this invention to remove or prevent the formation of such foaming, regardless of its origin. Another object of theinvention is to prepare finished cup greases which, due to being muchfreer from foam during the course of manufacture, are clearer andpresent a much better appearance.

Broadly, the invention comprises saponifying the fatty acids or otheracidic material in a twostage process by, for instance, using -50% ofthe lime in the first stage and heating the resultant reaction mixtureuntil reaction is complete, and any small amount of foam which may havebeen formed has disappeared due to reaction in the presence of an excessof acid, then subsequently adding the rest of the lime to complete thesaponification.

The preferredmethod of carrying out the invention is to dissolve a fattyacid such as stearic acid, hog fat acids, tallow acids, or othersuitable acidic materials in a suitable mineral oil base stock such asone having a viscosity between the approximate limits of 40 seconds and300 seconds Saybolt at 210 F., and heating the resultant mixture untilsatisfactory solution or dispersionis obtained, generally a temperatureof about 80 F. to about 125 F. is required, and then adding about 10-50%of the total amount of hydrated lime to be used in the saponification,this hydrated lime being added preferably in the form of a susablylikewise in the form of a lime-oil suspension,

and the heating and stirring continued until the saponification issubstantially complete. The grease may then be poured directly intocontainers for shipping orstorage.

The mineral oil to be used as base stock may be derived from parafilnic,naphthenic, or mixed base crudes and may be refined by conventionalmethods such as clay treating, acid treating, distillation, solventextraction, etc. Instead of using stearic acid or the other fattymaterials mentioned above, one may also use other conventional fattymaterials such as oleic acid, cottonseed fatty acids, or synthetic fattyacids derived by the oxidation of paraffln wax or other high molecularweight carboxylic acid having at least 10, and preferably more than 15carbon atoms, such as naphthenic acids obtained from petroleumhydrocarbon oils of the kerosene and higher boiling ranges.

Although the invention is intended to apply primarily to the preparationof cup greases in which lime is used as the saponifying agent, it mayalso be applied to the preparation of lubricating greases containingother types of saponifying agents than lime, as for instance sodagreases, aluminum soap greases, etc., particularly when such saponifyingagent contains traces Or substantial amounts of impurities in the formof carbonates or other compounds capable of giving off a gas whenreacted with fatty acids, particularly with the small amount of lowmolecular weight fatty acids, often present in commercial fatty acids.

In carrying out the invention, the first addition of lime maybemade-large and the mate rial cooked to dryness if desired to increasethe clarity of the product by the removal of water.

In the preferred continuous .process, the first mixing may be done in astorage tank, with or without heating, and the second addition of limemay be mixed in continuously after the first mixture has been heatedsufficiently.

As a still further alternative, the fatty acid raw material may bepartially reacted with some hydrated lime, before it is dissolved ordispersed A 400 pound batch of cup grease is made by using the followingformula:

Per cent Commercial oleic acid 8.0 Hydrated lime (first step) 0.2Hydrated lime (second step) 0.8

Lubricating oil (70 seconds Saybolt Universal at 210 F.) s 91.0

The lime was suspended in twice its weight of oil and the acid added tothe balance of the oil. of the lime suspension was added to the acidsolution which was heated to 190 F. Two hours later, the two mixtureswere blended in a tank.

The final completed batch of grease showed less than of an inch of foamas compared to over 1 inch of foam on a batch of grease made with thesame amount of materials but carrying out the saponification in a singlestep.

Thus, the essential feature of the present invention consists in heatingand stirring the mixture during the partially saponified stage to permitthe acid medium to break up the foam formed during the initial stage ofsaponification.

It is not intended that this invention be limited by the specificexamples which have been given merely for the sake of illustration, norunnecessarily by any theory as to the mechanism of the operation of theinvention, but only by the appended claims in which it is intended toclaim all novelty inherent in the invention as well asothermodiflcations coming within the scope and spirit of the invention.

What is claimed is: v i

i. The process of manufacturing a lime-s09. I

lubricating grease which comprises dissolving all of the fatty materialsto be used in a mineral oil base stock, dispersing hydrated lime inmineral oil, adding about 10-50% of said lime dispersion to theoil-solution of fatty materials and reacting the resultant mixture untilsaid lime is substantially completely reacted and until the foaminitially formed has substantially completely broken, and finally addingthe rest of the lime dispersion, and heating and stirring the mixtureuntil saponiflcation is complete, the entire reaction being completed ata temperature not exceeding about -200 F'.

2. A two-stage process for manufacturing cold made cup grease whichcomprises dissolving high molecular weight fatty acids in a mineral oilhaving a viscosity of about 40 to 300 seconds Saybolt at 210 F.,dispersing hydrated lime in a similar mineral oil base stock, addingabout 5-50% of the lime suspension to the fatty acid solution in oil,heating the resultant mixture to about F. until initially formed foamhas substantially completely broken, then adding the remainder of thelime suspension and heating and stirring until saponification iscomplete.

3. A two-stage process for manufacturing cold made cup grease from fattyacid lubricating oil and hydrated lime which comprises mixing all of thefatty acid with 98% by volume of the lubricating oil and heating theresulting mixture, suspending all of the hydrated lime in the remaining2% of lubricating oil into a homogeneous suspension, adding 20% byvolume of said suspension to the oil-fatty acid mixture with stirringand heating until the lime therein is substantially completely reactedwith the fatty acid, and then adding the remaining 80% of limesuspension with further stirring and heating until the saponificationreaction is complete.

ALAN BEERBOWER. RALPH E. DARLEY.

